Field test unit for a gas turbine fuel injection system

ABSTRACT

A unit is disclosed for field testing the nozzle manifold and fuel starting nozzles of a gas turbine engine. A portable case has a tank that is filled with fuel and pressurized to a predetermined level. The output of the tank is connected to the engine fuel nozzle manifold to test fuel distribution from the main nozzles. The engine starting nozzles are placed on a protractor nozzle support assembly to determine visually their spray pattern.

United States Patent Marcio et al.

[ 51 Aug. 1, 1972 [54] FIELD TEST UNIT FOR A GAS TURBINE FUEL INJECTIONSYSTEM [72] Inventors: Roger A. Marcio, New Haven; Orrin J. Winton,Bridgeport, both I of Conn.

[73] Assignee: Avco Corporation, Stratford, Conn.

[22] Filed: Feb. 16, 1971 [21] Appl. No.: 115,183

[52] US. Cl. ..73/119 A, 73/168 [51] Int. Cl. ..G0lm 15/00 [58] Field ofSearch ..73/119 A, 168, 3; 222/399 [56] References Cited UNITED STATESPATENTS 1,750,512 3/1930 Ewald ..222/400.7

2,066,397 1/1937 Fogarty ..222/395x 2,504,009 4/1950 Phillips etal..222/400.7x

Primary Examiner-Jerry W. Myracle Att0rneyCharles M. Hogan and Gary M.Gron 57] ABSTRACT A unit is disclosed for field testing the nozzlemanifold and fuel starting nozzles of a gas turbine engine. A portablecase has a tank that is filled with fuel and pressurized to apredetermined level. The output of the tank is connected to the enginefuel nozzle manifold to test fuel distribution from the main nozzles.The engine starting nozzles are placed on a protractor nozzle supportassembly to determine visually their spray pattern.

2 Claims, 2 Drawing Figures PATENTEDAUG 1 m2 INVENTORS. ROGER A. MARCIOORRIN J. WINTON in. 7. ATTORNEYS.

FIELD-TEST UNIT FOR A GAS TURBINE FUEL INJECTION SYSTEM The presentinvention relates to the testing of gas turbine engines and moreparticularly to the fuel systems used in this type of engine.

The gas turbine engine from its very inception has been a highlycomplicated machine requiring sophisticated maintenance procedures. Theneed for complicated instrumentation and special tooling requires thatengines be sent to major service and overhaul facilities, therebysubstantially increasing the time and expense of engine maintenance.Thishas been particularly true of gas turbine fuel systems where themany conduits, nozzles and controls need to be disassembled and testedwith bench units to determine their performance.

Accordingly, it is an object of the present invention to enable thequick, efiicient and effective testing of the fuel system of a gasturbine engine in the field.

These objects are achieved by a field test apparatus comprising aportable case which has in it a component for supplying a source of fuelat a predetermined sufficient pressure to cause flow through thecomponents of the fuel injection system. A conduit assembly extendingfrom the fuel supply component can be connected to an engine main nozzlemanifold or a fuel starting nozzle so that their flow characteristicscan be tested.

The above and other related objects and features of the presentinvention will be apparent from a reading of the description of thedisclosure shown in the accompanying drawing and the novelty thereofpointed out in the appended claims.

In the drawing:

FIG. 1 is a plan view of a field test unit embodying the presentinvention, along with several gas turbine engine fuel system componentsthat may be tested by the unit;

FIG. 2 is a section view of the field test unit shown in FIG. 1, takenon lines 2-2 of FIG. 1.

Referring now to FIGS. 1 and 2 there is shown a field test unitcomprising a portable case which is used to house the components of thefield test unit. The unit is shown in its test condition in FIG. 1 butfor transport conditions has a suitable cover (not shown) to protect thecomponents of the unit.

The test unit has a series of pressure gauges 12 mounted to a cover 14on case 10. The gauges are connected by conduits (not shown) tocouplings 16 extending from cover 14. The couplings are connected tovarious equipment in the engine to enablea determination of theirperformance, such as: the pressure output of a fuel pump; the output ofa hydraulic pump; or the pressure required to display a particularactuating device. These items are mentioned only to indicate that thecase 10 may incorporate testing equipment other than the fuel injectiontesting apparatus particularly described below.

The apparatus for testing the fuel system components of the gas turbineengine includes a tank 18 formed by a cylinder 20 having a first endplate 22 and a second end plate 24. The end, plates 22, 24 form aninterior chamber 26. A valve housing.28 is threaded into opening in endplate 24. A longitudinal passageway 32 extends through housing 28 andopens I into the interior chamber 26. A pair of passages34 and 36 extendat right angles from passage 32. A removable cap 38 is provided over theend of passageway 34 to.

from valve 40 to hold the tank pressure. A suitable valve for thispurpose is marketed by the Schrader Division of the ScovillManufacturing Company, Nashville, Tennessee, under the part designationNo. 798, also MS 28889-1.

A conduit 42 is spaced from the walls of and extends throughlongitudinal passage 32 from a fitting 44 in an outer wall of housing 28and is bent to provide an inlet 46 in the lower portion of chamber 26. Acoupling 48 connected to fitting 44 has a conduit 50 which leads to aT-connection 60. A pressure release valve 52 and an operator manipulatedflow control valve 54 are interv posed in conduit 50. Flow through valve54 is permitted or blocked by twistingan operator manipulated knob 56. Afuel filter 58 is downstream of the flow control valve 54. A conduitassembly 88 extends from conduit 50 downstream of the filter 58 to apressure gauge 90.

A conduit 62 extends from one branch of the T connector to an outletconnector 64. Fitting 64 is adapted to receive a flexible conduit 92which extends to a main fuel nozzle manifold 94 having a series ofnozzles 96 connected to it. When the main fuel manifold is not beingtested a cap 66 is provided, as shown in FIG. 2. j

A second conduit 68 extends from the T connector 60 to a nozzle supportunit 70 which comprises a generally L-shaped base 72 and an extensionconduit 74 leading to a fitting 76 that receives a fuel starting nozzle78, as shown in FIG. 1. When a starting nozzle is not in place a cap 80is threaded onto element 76, as shown in FIG. 2.

The spray pattern of the starting nozzle 78 is determined by aprotractor having exterior diverging sides 102. The angle 0 that thesides 102 make with one another is selected to coincide with the spraypattern of a properly functioning nozzle 78. Protractor 100 is securedby screws 104 to an arm 106. Arm 106 is slidably received in a passage108 in a mounting block 110 secured to cover 14 by screws 112. A setscrew 1 l4 filled with a sufficient amount of fuel. Cap 38 is replacedover passage 34 and an air pressure line (not shown) is connected to thevalve 40 with caps 66 and 80 on connectors 64 and 7 6, respectively andflow control valve 54 open. The valve 40 is twisted to an open positionand the tank is pressurized to a level which is sufficient to produceuniform flow in the manifold and the nozzles. It has been found thatpressures of around 100 p.s.i. provide quite acceptable results. Oncethe pressure in chamber 26 has reached the predetermined level, asobserved on gauge 90, the valve at 40 is twisted to a closed positionand the air pressurizing line is removed from valve 40. The knob 56 onvalve 54 is twisted to a closed position and either the starting nozzleor the nozzle manifold is tested.

Assuming that the fuel manifold is tested first, the cap 66 is removedfrom fitting 64 and the flexible line 92 connected. The fuel nozzlemanifold which for most engines is readily removable from the engine asa unit,

is placed in a position to be observed by the operator of the equipment.The knob 56 on valve 54 is opened to permit flow through the nozzlemanifold 94 and the distribution and performance of flow through thenozzles 96 is visually determined. It has been found that fuel nozzleclogging can be quickly spotted using this technique.

Once this operation has been completed, valve 54 is closed, conduit 92removed and cap 66 placed 'on fitting 64. After this is done, cap 80 isremoved from fitting 76 and a starting nozzle 78, which is also easilyremoved from most engines, is threaded onto fitting 76.

The protractor 100-and its supporting arm 106 are adjusted by means ofthe set screw 114 to line up the point of convergence of the sides 102at the nozzle opening. After this is done the knob 56 is manipulated topermit flow through the nozzle assembly. The spray pattern from thenozzle is visually determined using the sides 102. lf-the pattern justcovers the protractor 100 it is properly functioning. A spray cone angleoutside or inside the sides 102 indicates plugging or anothermalfunction. When this test has been completed valve 54 is closed, thenozzle 78 removed and cap 80 placed on fitting 76.

When the field test of the fuel injection equipment has been completedthe protractor 100 and supporting arm 106, extending outboard of thecase 10, are removed from passage 108 and inserted from the opposite endof passage 108 so that the protractor 100 and arm 106 are entirelycontained within the bounds of case 10, as shown by the phantom lines inFIG. 1. In like manner the nozzle support fitting 76 and arm 74 arepivoted to the phantom position of FIG. 1 so that they are completelycontained in the limits of case 10. The unit is thus ready for transportuntil such time as the fuel injection components are to be tested whenthe above procedure would be reversed.

The above unit provides a highly effective and rapid means of fieldtesting the most important fuel injection components of a gas turbineengine in the field. The use of the pressurized tank enables a highlyaccurate and repeatable fuel flow and pressure in order to provideaccurate results. The starting nozzle support and the protractor arequickly positioned outboard of the case 10 so that the fuel thusdischarged will not spill onto the unit. However, these units arequickly placed in a transport position to enable a compact unit fortransport.

While the preferred embodiment of the present invention has beendescribed, it is apparent to those skilled in the art that othermodifications maybe performed without departing from its spirit andscope.

Having thus described the invention, what is claimed as novel anddesired to be secured by Letters Patent of the United States is:

1. Apparatus for field testing the fuel injection system of a gasturbine engine, said apparatus comprisa portable case;

a tank mounted within said case;

a valve-element housingintegralwith one end of said tank, said valvehousing having a longitudinal bore formed therein having a first closedend and a second end open to the interior, of said tank and a pair ofpassageways extending from said longitudinal bore generally at rightangles thereto;

releasably attached caps for said right angle passageways, onepermitting the entrance of fuel and the other permitting the entrance ofair under pressure;

a conduit spaced from the walls of and extending from the exterior ofsaid valve element housing through the first end of saidlongitudinalbore and through the second end of said bore to a bottomportion of the tank;

. an operator-manipulated flow control valve series connected to anddownstream of said tank for controlling flow of fuel therefrom; conduit.means extendingv from said flow control valve and having a pair ofoutlets for enabling selective application of the output thereof to anengine main nozzle manifold and to fuel starting nozzle whereby the flowcharacteristics of said assemblies may be tested;

means on said case for releasably supporting a fuel nozzle at one outletof said conduit means;

a protractor having divergent sides with a predeter-' mined angletherebetween;

means for releasably supporting said protractor adjacent said nozzlesupport means in a first position extending outward from said casing fortesting said nozzle and a second position fully contained within saidcase for transport therewith;

said nozzle support means comprising a conduit extending. from saidconduit means and being pivotal from a first position extending outwardfrom said casing for testing said nozzle and a second position whereinsaid nozzle is fully contained within said case.

2. Apparatus as in claim 1 wherein said releasable mounting meanscomprises:

a support having a passage therethrough opening on one side toward theexterior of said case and on the other side toward the interior of saidcase;

an arm supporting said protractor and slidable into said passageway fromeither end; and

a set screw releasably holding said arm in said passageway whereby insaid first position said shaft is inserted in said passageway from theexterior of said case and in said second position said shaft is insertedin said passage from the interior. portion of said case.

1. Apparatus for field testing the fuel injection system of a gasturbine engine, said apparatus comprising: a portable case; a tankmounted within said case; a valve element housing integral with one endof said tank, said valve housing having a longitudinal bore formedtherein having a first closed end and a second end open to the interiorof said tank and a pair of passageways extending from said longitudinalbore generally at right angles thereto; releasably attached caps forsaid right angle passageways, one permitting the entrance of fuel andthe other permitting the entrance of air under pressure; a conduitspaced from the walls of and extending from the exterior of said valveelement housing through the first end of said longitudinal bore andthrough the second end of said bore to a bottom portion of the tank; anoperator-manipulated flow control valve series connected to anddownstream of said tank for controlling flow of fuel therefrom; conduitmeans extending from said flow control valve and having a pair ofoutlets for enabling selective application of the output thereof to anengine main nozzle maNifold and to fuel starting nozzle whereby the flowcharacteristics of said assemblies may be tested; means on said case forreleasably supporting a fuel nozzle at one outlet of said conduit means;a protractor having divergent sides with a predetermined angletherebetween; means for releasably supporting said protractor adjacentsaid nozzle support means in a first position extending outward fromsaid casing for testing said nozzle and a second position fullycontained within said case for transport therewith; said nozzle supportmeans comprising a conduit extending from said conduit means and beingpivotal from a first position extending outward from said casing fortesting said nozzle and a second position wherein said nozzle is fullycontained within said case.
 2. Apparatus as in claim 1 wherein saidreleasable mounting means comprises: a support having a passagetherethrough opening on one side toward the exterior of said case and onthe other side toward the interior of said case; an arm supporting saidprotractor and slidable into said passageway from either end; and a setscrew releasably holding said arm in said passageway whereby in saidfirst position said shaft is inserted in said passageway from theexterior of said case and in said second position said shaft is insertedin said passage from the interior portion of said case.